1. Field of the Invention
The present invention relates to a gas-liquid separator and a fuel cell system having the same, in which only gas components outwardly exhaust from materials discharged from an electric generator of a fuel cell, and more particularly, to a gas-liquid separator capable of allowing carbon dioxide to be exhausted to the atmosphere so as to recover and recycle only unreacted fuel discharged from an electric generator, and a fuel cell system having the same.
2. Description of the Related Art
In general, a fuel cell system is a power generation system that directly transforms chemical energy into electric energy through electrochemical reaction between hydrogen of hydrogen containing fuel and oxygen of an oxidant. Such a fuel cell system comprises an electric generator to generate electricity, a fuel feeder to supply the hydrogen containing fuel to the electric generator, and an oxidant feeder to supply the oxidant to the electric generator. Further, the fuel cell system comprises an unreacted fuel recovering unit such that the unreacted fuel and steam discharged from the electric generator are recovered and reused.
The electric generator has a stack in which a plurality of unit cells to generate electricity is stacked. The unit cell comprises a membrane electrode assembly (MEA) that includes an anode electrode, a cathode electrode, and an electrolyte membrane interposed between the anode and cathode electrodes, and separators, e.g., bipolar plates, both surfaces of which face the anode and cathode electrodes, respectively, and are formed with channels through which fluid can flow.
The bipolar plates not only provide the anode and cathode electrodes with reactants such as the hydrogen containing fuel and oxygen, respectively, but also discharge products such as carbon dioxide and water from the anode and cathode electrodes to the outside, respectively.
The hydrogen containing fuel, which is not reacted in the anode electrode, produces unreacted hydrogen containing fuel. The unreacted hydrogen containing fuel exhausted from the anode electrode is recovered through the unreacted fuel recovering unit and supplied into the electric generator.
While unreacted hydrogen containing fuel is recovered through the unreacted fuel recovering unit, carbon dioxide produced in the anode electrode may be recovered as it is mixed with the unreacted hydrogen containing fuel. At this time, if recovered carbon dioxide is supplied to the anode electrode of the electric generator, power generation efficiency of the fuel cell is reduced.